THE FOUR MOMENTS OF THE SUN: KONGO ART IN TWO WORLDS-- At the National Gallery of Art East Building, Sunday through January 17.

Kongo art shows time as a cycle, with life clocking in at dawn, flourishing at noon, expiring at sunset and reaching a matching zenith at midnight when the sun shines on the kingdom of the dead. If it's been a good life, the sun dawns and the circle is unbroken.

"The Four Monents of the Sun: Kongo Art in Two Worlds," opening Sunday at the National Gallery's East Building for the next serveral months, presents 58 examples of cloth, wood, terra cotta and soft stone sculpture. The grave markers, funeral trumpets and other funerary artifacts reflects intricate religious and philosophical meanings as well as esthetic values.

The show holds added signifiance for those of Kongo and Angolan ancestry, which includes about a third of all blacks in America. From language to rock'n roll acts, Kongo influences on this country and its cutlture are evident. One panel lists six words in Ki-Kongo, in Afro-American translation and finally in English (nguba, goober, peanut; tuta, tote, carry). Bottle trees used to arrest evil spirits, a Kongo tradition, and jug players at New Orleans black jazz funerals are depicted in photomurals. Even The Supremes' stance on the first word of their song, "Stop! In the Name of Love," is cited as an American pop-culture derivative of a Kong pose.

Kongo with a K refers to the traditional Bakongo territory, not Zaire and neighboring Central Africa, and a way of life dating back more than 600 years. People of Bakongo have a saying: "Every problem is a symbol of dying." But those who've lived well are believed to die twice, once here, once there ; thus the "two worlds." Saturday poses and carved designs refer to meditation and spiritual dialouge with the beyond. Recurring emblems like crosses, circles, diamonds and snail-shell spirals signify the four moments of the sun, circling the intertwined worlds of life and death. (Scholars say the Kongo cross predates the coming of the Portuguese with the crucifix.)

The gallery halls are alive with the sound of funeral trumpets. Gesturing wood statues, actually one-note horns, are exhibited to the tune of their dull, hollow sound on tape. A monumental eight-foot cloth figure used to transport the mummified body of some important female to her grave towers over the show, and the hand signals of other cloth mannequins are worth puzzling over.